1. Field of the Invention
The present invention relates to a mirror-driving mechanism for single-lens reflex cameras, and more specifically to an improvement in an interlocking mechanism between a first observation mirror and a second mirror for guiding luminous fluxes to the underside of a mirror box.
2. Description of the Prior Art
As a mirror-driving mechanism for a single-lens reflex camera comprising a first mirror for observation and a second mirror provided rotatably with respect to the first mirror, there has been employed a mechanism wherein when observation is made, the second mirror is brought into abutment against a locating stopper by means of an urging spring, and at the time of photographing, the second mirror is brought into engagement with a defining cam surface by the upward rotating force of the first mirror in order to reverse the urging direction of the urging spring to bring the second mirror into resilient contact with the back surface of the first mirror.
However, in conventional mechanisms, when the urging direction of the second mirror is reversed, a pin provided on a second mirror holding frame is caused to impinge upon the defining cam surface by the snap action of the urging spring, or a second mirror holding frame is caused to impinge upon the first mirror holding frame, thus generating shock noises, shocks and the like. Such shocks, vibrations or the like generated at the final stage of upward movement of the mirror often result in apparent deflection of the camera, thereby adversely affecting photography.